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Assessment of the International Symposium on Spray Dried Dairy Products

December 14, 2012 by Marion GUILLOT

10 million tons of dairy powders produced every year but only 1 dedicated international colloquium! Read here a summary of the presentations.

In June took place in St Malo (France) the 5th International Symposium on Spray Dried Dairy Products (SDDP). For the first time jointly organized by the International Dairy Federation (IDF) and the Institut National de la Recherche Argonomique (INRA), the Scientific committee directed by Pierre Schuck made a balanced choice between scientific research and industrial technology development as each parties issues are very often inter-connected.

3 days, about 500 participants, a half of them researchers, 38 countries, 65 academic presentations, 20 industrial presentations, 52 scientific posters, 5 workshops, 74 companies and 44 sponsors to understand, highlight and improve the spray drying process. All this in order to have a better control and a clear modelization of the different products and processes implied.The technological advances were also presented by the main facilities manufacturers.

Why dehydrate?

Dehydrating milk lengthens its shelf life, reduces its volume and the transportation costs.

But the process is very complex and faces empirical knowledge. The principle issue of the spray drying process is determining and taking into account the interaction between the process and the product during the drying phase to master the dehydration without altering the product.

Whey powders enter in formulation in industrial processes (food industry, pharmacy) and, as the world’s consumption is evolving very quickly with the emergence of developing countries, these ingredients play an increasing role in the world’s economy and importation figures.

Drying is also a key issue for governments in developing countries, as a potential source of growth for companies who want to expand nationally and worldwide thanks to a technological advance.

In a few words, here are the main tendencies expressed during the 5 sessions:

It was not just an academic research session; the discussed themes were of great concern for technology industries and researchers: quality problems such as stickiness, importance of the process parameters on the final quality, alteration of casein micelles with consequences upon powders functionalities, treatment difficulties of high concentrated products like proteins, etc.

From the small scale of a laboratory, speakers extrapolated to reach the gigantic industrial scale.

One of LISA's expert during a presentation entitled "Prediction of drying of dairy products using a modified weight scale-based desorption methdod"

Session 2 - Whey and by-products:Lactose and Crystallization

This session dedicated to whey and by-products, and particularly lactose, exposed the problems found in the modelization of lactose crystallization in different conditions. The posters concerning serum protein hydrolysates powders behavior and the effect of microparticulation before drying on its functional properties gave results which open new horizons for applications using whey proteins.

Environmental and economical concerns were the main point of this session.

Optimization and improvements in the lyophilization process of lactiques bacterias cultures now offer better quality products, especially in the cheese production.

Another presentation made us discover the LES method (Large Eddy Simulation) : it enables one to visualize air streams and their progress in a semi-industrial (60m3) drying tower during the drying phase. It showed that these streams are quite unpredictable and hard to modelize: even on long observation periods, no cycle can be identified.

Finally, another interesting innovation for the production of powders coming from high concentrated and viscous products was presented. The process called EPT (Extrusion-Porosification-Technology) is simple: extrusion (with a gas injection) and drying. The result is porous grain powders easily rehydratable: this is really helpful for milk proteins powders like “native caseins”. It saves energy (40% - estimation) and time in comparison with the normal process.

Powders analysis and their reactivity were debated in this session. More academic than the other, it was interesting to learn about the precise mechanisms of powders stickiness, the use of ultrasounds to follow the rehydration process, a deep analysis of conglomeration technologies and also the determination of grain powders surface composition, in lactose, fats and proteins, on different layers thanks to x-ray technics.

All these technics highlight the constant improvement in technology and forecast the future technological great advances.

Session 5 – Commercial session: optimizing the dairy production

To root this Symposium in factories’ daily reality, this session enabled equipment manufacturers to present their products and their particularities.

A unique session as in this kind of event nutrition is hardly a subject of discussion. Nutritional values were the main point: the interest of ultra-low heat skimmed milk powders as main matrix for the study of dairies’ nutritional qualities, the micro-encapsulation of probiotic bacteria, and a process to obtain a 73% protein buttermilk powder, enriched in phospholipids (around 12%), combining filtrations and one extraction by super critic CO2.